exchange transfusion

transfusion

[trans-fu´zhun] the introduction of whole blood or blood components directly into the blood stream. Among the elements transfused are packed red blood cells, plasma, platelets, granulocytes, and cryoprecipitate, a plasma protein rich in antihemophilic factor VIII. The current trend is to transfuse blood components rather than whole blood because by so doing the utility of each unit of blood can be extended and the treatment provided more nearly meets the specific needs of the patient.

Transfusion is most often indicated to maintain or replace blood volume, to provide deficient blood elements and improve coagulation, to maintain or improve transport of oxygen, and in exchange for blood that has been removed in the treatment of Rh incompatibility in the newborn, liver failure in which toxins accumulate in the blood, or in some other types of toxemia.Transfusion Methods. There are several different methods of transfusion. Direct transfusion, in which blood from one person is directly transferred to another person, is now rarely used. The usual method is indirect transfusion, in which blood is drawn from a donor, stored in a sterile container and later given to a recipient. Exchange transfusion, in which blood is removed from a person and simultaneously replaced by donor blood, is used mainly in treating erythroblastosis fetalis.Intrauterine or Fetal Transfusion. Intrauterine transfusion involves direct transfusion of Rh negative packed red blood cells into the fetal peritoneal cavity. It is done for the early treatment of pronounced degrees of fetal isoimmunization before weeks 32 to 34 of pregnancy.

The first step is injection of a radiopaque dye into the amniotic fluid. After the fetus ingests the dye, the intestinal tract can be visualized by radiographic techniques so that it serves as a guidepost for location of the abdominal cavity. A long pudendal needle is then inserted through the mother's abdomen and guided through the uterine wall, through the fetal abdomen, and into the peritoneal cavity. Another radiograph is taken to confirm correct placement of the needle and then the erythrocytes are transfused. The erythrocytes soon pass into the fetal blood stream. This procedure is obviously not without hazard and is done only if the fetus cannot be expected to survive without it. The treatment usually is done every 7 to 10 days until delivery. Once the newborn is delivered, transfusion" >exchange transfusion and supportive therapy are begun.Blood Typing and Crossmatching. Transfusions were not practicable until the four main hereditary blood groups, A, B, AB, and O, were discovered at the beginning of the 20th century. Until these blood types were identified, antigen-antibody reactions could not be predicted and transfusion reactions (often fatal) were a matter of chance. There are certain antigens on the surface of red blood cells which can precipitate a transfusion reaction when incompatible blood types are mixed. In the ABO system the types are dictated by A antigen and B antigen. There is also an allele O that does not code for either A or B antigen. Thus there are four possible groups (A, B, AB, O). A person who is type A has only A antigen on red cells; one who is type B has only B antigen; one who is type AB has both A and B antigens; and one who is type O has neither. All individuals produce antibodies against the A or B antigens that are lacking on their own cells. Thus, type A has anti-B; type B has anti-A; type O has both; and type AB has neither.

Rh negative individuals lack D antigen on red cells. They do not produce anti-D antibodies unless they are directly exposed to Rh positive blood, as may occur from a fetal-maternal hemorrhage or from transfusion of platelet or granulocyte concentrate containing Rh positive red cells.
Another system of blood typing is sometimes considered prior to transfusion of granulocytes or for long-term platelet administration. The typing identifies the hla antigens that occur on leukocytes and platelets. (See also tissue typing.)
Crossmatching is another way in which blood is tested for compatibility prior to transfusion. It involves placing the cells of the donor in a sample of the recipient's serum, and cells of the recipient in a sample of the donor's serum. Absence of agglutination, hemolysis, cytotoxicity indicates that the blood specimens are compatible.Adverse Reactions. Among the most common transfusion reactions are reactions" >antigen-antibody reactions resulting from blood type incompatibility. When blood groups are incompatible there is agglutination (clumping) of cells, hemolysis, and release of cellular elements into the serum. Signs and symptoms indicating such a reaction include burning sensation along the vein where the transfusion is given, facial flushing, chills and fever, headache, low back pain, rash, red urine, and shock. Other reactions include febrile reaction, allergic reaction with hives, wheezing, and anaphylaxis, and response to bacterial contamination. See accompanying table.

Every health care agency in which transfusions are administered should have a written policy regarding the correct steps to take in the event a patient begins to show signs of a reaction. In general, should such signs occur, the transfusion is stopped immediately, the venous line is kept open with normal saline, and emergency care is initiated.
Especially dangerous to patients with either cardiac or renal disease is hyperkalemia, an excess of potassium in the blood. If the condition is not corrected, a flaccid paralysis develops, affecting the muscles of respiration and eventually the heart muscle, which can lead to cardiac arrest. High levels of potassium in donor blood are likely to occur when the bank blood is several days old. It is estimated that the breakdown of red cells in the stored blood increases the level of potassium at the rate of one milliequivalent per liter per day.
Another possible complication is hypocalcemia, which can occur when large amounts of blood containing the additive acid citrate dextrose are given rapidly, as to a bleeding patient. Acid citrate dextrose is an anticoagulant that binds with calcium ions in the recipient's blood, removing them from circulation and thereby reducing the calcium level below that essential for normal coagulation.
Circulatory overload is a possibility any time blood is administered rapidly in large amounts. Patients who are particularly susceptible to this eventuality are the very young, the very old, and those suffering from a pre-existing cardiopulmonary or renal problem. Another difficulty that may be encountered when blood is administered rapidly under pressure is that of air embolism.autologous transfusion reinfusion of a patient's own blood, done by either of two methods: (1) patients having a planned surgical procedure may donate their own blood within six weeks before surgery; the donated blood is processed, frozen, stored, and then thawed for use at the time of surgical need; or (2) blood lost during the operative procedure may be salvaged; this is also called autotransfusion. In the second method, blood and debris from the surgical field are aspirated into a collection chamber containing a dilute solution of heparin or citrated dextrose. The aspirate is filtered and pumped into a centrifuge chamber and the red cells are then washed with a normal saline solution. Centrifugal force separates the red cells from waste products such as debris, plasma, hemolyzed red cells, platelets, most white cells, and solution such as anticoagulant or antibiotic irrigation solution. The washed packed red blood cells are then pumped into a blood infusion bag and reinfused into the patient in the usual manner.exchange transfusion transfusion in a newborn infant of packed cells or fresh whole blood that is type O, Rh-negative, and previously cross-matched with the mother's serum, or Rh negative blood of the same type as the newborn's. Rh negative blood is used because, even though the newborn may have Rh positive blood, maternal antibodies that entered the fetal bloodstream in utero are still present in the newborn and would destroy the transfused blood cells. The blood is transfused via the umbilical vein. Exchange transfusion is used to treat either moderate to severe hemolytic disease of the newborn or hyperbilirubinemia not controlled by phototherapy. Complications may include heart failure due to either hypervolemia or hypovolemia, bradycardia or cardiac arrest from acidosis or hyperkalemia, hypocalcemia, hypothermia, air emboli, thrombolytic emboli, sepsis, intensification of hypoglycemia, and thrombocytopenia if there are repeated exchange transfusions.fetomaternal transfusion transplacental passage of fetal blood into the circulation of the mother; in small amounts it may go unnoticed, but in larger amounts it can cause anemia or edema in the fetus.intrauterine transfusion direct transfer of Rh negative blood cells into a fetus in utero in cases of isoimmunization" >isoimmunization; see transfusion" >transfusion.placental transfusion the transfer of blood from placenta to newborn at the time of birth. Blood flow through the umbilical arteries stops about 45 seconds after birth, but the umbilical vein remains patent longer. Uterine contractions enhance the transfer of blood, the volume of which has significant physiological benefits to the neonate. Since gravity influences this transfer, raising the newborn above the level of the placenta prevents a normally occurring placental transfusion. Conversely, lowering the newborn below the placental level accelerates the process.transfusion reaction any symptoms due to agglutination or hemolysis of the recipient's blood cells when blood for transfusion is incorrectly matched. See discussion under transfusion.

ex·change trans·fu·sion

removal of most of a patient's blood followed by introduction of an equal amount from donors. Synonym(s): exsanguination transfusion, substitution transfusion, total transfusion

exchange transfusion

Neonatology A therapeutic procedure for reducing immunotoxins in the neonate by administration of compatible packed RBCs Indications HDN–due to maternal IgG antibodies against fetal antigens; neonatal hyperbilirubinemia, due to RBC and bilirubin metabolic defects Complications Thrombocytopenia, iron deficiency, HBV–rare, HIV–very rare

ex·change trans·fu·sion

(eks-chānj' trans-fyū'zhŭn) Removal of most of a patient's blood followed by introduction of an equal amount from donors.
Synonym(s): substitution transfusion, total transfusion.

exchange transfusion

The treatment given urgently to all babies with severe haemolytic disease of the newborn (ERYTHROBLASTOSIS FETALIS) from rhesus incompatibility with the mother. A fine catheter is passed along the umbilical vein into the main vein of the body (the inferior vena cava) and 20 ml of blood is withdrawn and replaced by 20 ml of donor blood. This is repeated about eight times.

exchange transfusion

exchange transfusion

exchange transfusion

exchange transfusion

transfusion

ex·change trans·fu·sion

exchange transfusion

ex·change trans·fu·sion

exchange transfusion

exchange transfusion

Words related to exchange transfusion

noun slow removal of a person's blood and its replacement with equal amounts of a donor's blood

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